make Cavern of Chaos easier

some of the CoC are simply absurd, for example, the frozen skeletons with consistent 2+ roll armor 6 [except against fire] against no fire mages or fiery stabs. The 10th level is also extremely absurd since you only have three characters against a dragon combined with some other characters. The dragon itself is very difficult, as even in normal campaign mode the yellow dragon [as an example] isn't exactly easy to beat. IMO you should be given maybe five characters, or keep three but only battle the dragon. Once I drew the exceptionally tanky and helpful Bleneth with a hand of double enchanted harness and officer's harness, but against noxious breath... ugh.
I enjoy a challenging battle, but no one likes an outright impossible battle. Anyone with me here?

Bonus elaboration to the 5 characters: I think it would actually be really fun to have Mauve Manicore 9's necromania heroes setup [Boppsy, Cuddlepie, Mr. Jingles, Idris, dog boy] against a random dragon among other monsters. I really like playing around with three OP characters, a helper, and a strong mage. Give a stronger edge to the fight rather than seemingly hopeless.

Indeed sometimes the battle is very obviously impossible.
but oddly , even i knew it was impossible , i never easily resigned ,

i guess the most satisfying part about doing CoC
is beating something which i thought was almost "impossible" to beat
and then repeatedly improve my ability to define "possible".

But i do agree that there are a lot of things can be done to make CoC funnier~
for example : let us choose 3 chars out of 4 at the start of each battle~~!
so that we could be more comfortable to not get mad at the RNG. XD

Dude, the dragon you got, Greenfang is the easiest one. And you had a legendary hero to face him too. You don't always get that one. CoC is far easier since it first came out. You just need to get better. At one point I challenged myself to complete it every day. I managed to do it for 3 days in a row (and one of those days I beat it twice, consecutively) but then abandoned the idea because I didn't have 2-3 hours to spend everyday. But to get to that point it took me 6 months to score my first victory. How to get better you ask?
Learn the decks of your opponents and your heroes. And how they behave. If you knew the deck the dragon you faced had, you wouldn't be complaining about the armor removal you got.

Some of the time, a Caverns level isn't 'winnable' - but a lot of the time, it is. I took notes on my last series of runs to a completion here, and not counting the first level (where you have your own characters), my win/loss rate for each level was 64 to 13, or ~83%. Some of the characters are weak, some of the maps are bad, and some of the mobs are very, very tough, even more so if you have the wrong characters to deal with them. Example: 4 x security robots + 4 x storges + other mobs vs three priests on the third Cardstock II map (the open bridge one). Of course, that combination is almost impossible.

Caverns is old school and is meant to punish you until you get good, and then punish you some more until you get lucky as well. But it's not impossible. I probably average a run every 2-3 days since it's been released, and I've completed it nearly 20 times, including three times since the CM monsters were added.

I really like Stupid's suggestions though. I've scraped through levels where I was certain I was cooked, including taking out a full health oak bombardier with a 1HP dwarf mage.